Automatic Transmission Cheddar
Automatic Transmission allows the driver to be free from having to change gears manually.
The most common type of automatic transmission is hydraulic. This system uses fluid coupling in place of the manual’s friction clutch, and changes gears by locking and unlocking a system of planetary gears.
The normal lettering you see on an automatic are P R N D (Park, Reverse, Neutral, Drive)
Automatic Transmission Modes
This selection mechanically locks the output shaft of transmission, restricting the vehicle from moving in any direction.
A parking pawl?prevents the transmission from rotating, and therefore the vehicle from moving. However, it should be noted that the vehicle?s non-driven wheels are still free to rotate, and the driven wheels may still rotate individually (because of the differential). For this reason, it is recommended to use the hand brake (parking brake)?because this actually locks the wheels and prevents them from moving.
It is typical of front-wheel-drive vehicles for the parking brake to lock the rear (non-driving) wheels, so use of both the parking brake and the transmission park lock provides the greatest security against unintended movement on slopes. This also increases the life of the transmission and the park pin mechanism, because parking on an incline with the transmission in park without the parking brake engaged will cause undue stress on the parking pin, and may even prevent the pin from releasing. A hand brake should also prevent the car from moving if a worn selector accidentally drops into reverse gear while idling.
A car should be allowed to come to a complete stop before setting the transmission into park to prevent damage.
Usually, Park (P) is one of only two selections in which the car?s engine can be started, the other being Neutral (N).
In many modern vehicles, the driver must have the foot brake applied before the transmission can be taken out of park.